Responding to a seemingly benign question about the opportunities afforded to Facebook by Apple's new mobile operating system, Zuckerberg launched into a brief appraisal of the state of play in the mobile OS field. There are three main platforms, he said: Google's Android, Apple's iOS, and the mobile Web. He praised Android for the relative openness of its system, which, for instance, allows people to send text messages via the Facebook app. Then his tone turned a little peevish.

Advertisement

"Android is a very dynamic and open platform—as long as Google keeps it that way," he said. Then he added, "Our relationship isn't one where the companies really talk."

Apple, in contrast, has "a more locked-down system," he noted, but "they've been a great partner for us so far."